AUTHOR=Nagai Masahiro , Koebis Michinori , Sasaki Kotaro , Kobayashi Chizuru , Daidoji Kasumi , Ishida Takayuki 

TITLE=Persistence and adherence to levodopa adjunct medications in elderly patients with Parkinson’s disease: a retrospective cohort study using a Japanese claims database

JOURNAL=Frontiers in Neurology

VOLUME=Volume 16 - 2025

YEAR=2025

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2025.1560431

DOI=10.3389/fneur.2025.1560431

ISSN=1664-2295

ABSTRACT=ObjectiveWe investigated treatment persistence and adherence for levodopa adjunct medications and their relationship with demographic factors in Japanese patients with Parkinson’s disease (PD).MethodsThis longitudinal retrospective study used a Japanese health insurance claims database for levodopa adjunct medications in patients newly prescribed anti-PD drugs other than levodopa between December 2020 and November 2021. Patients with a PD diagnosis were included in this study, and 17 anti-PD drug cohorts were formed. The primary outcomes were treatment persistence and adherence over 1 year. Multivariate analysis was conducted to evaluate demographic factors associated with treatment persistence/adherence.ResultsIn total, 7,605 patients were included in this analysis, with a mean age of 77.2 years, and 43.6% were male. The 1-year treatment persistence rate was 44.8%. Median persistent treatment duration over 1 year was 270.0 days. Persistence rates ranged from 28.6 to 59.5% across the drug cohorts, and were highest for zonisamide (59.5%) followed by safinamide (55.8%). The proportion of patients with proportion of days covered ≥80% (good treatment adherence) was 96.9% in the all-drugs cohort and ≥ 90% in each drug-specific cohort. In the multivariate analysis, the factor most strongly associated with non-persistence was the number of concomitant anti-PD drugs (risk ratio [RR] 0.85 per 1 unit increase), with the exception of inpatient prescriptions (RR 0.75).ConclusionMore than half of the new anti-PD drugs added to levodopa were discontinued within 1 year, and adherence to treatment, as assessed by filling records, was extremely high in patients with PD, including the elderly population.